Such control means are described in Patent Document DE-B-1 003 321.
As described in that prior document, the communication duct is provided with an orifice that is open to atmospheric air, and with a valve having two seats. In the engagement position, the valve closes the duct enabling the gas to pass from the interrupting chamber to the active face of the piston, and, in the disengagement position, it closes that portion of the duct which communicates with the interrupting chamber so as to open the orifice to that portion of the duct which communicates with the cylindrical element, thereby removing the gas to the outside, reducing the pressure on the active face of the piston, and separating the contacts of the circuit-breaker.
Although they offer the advantage of using the pressurized dielectric gas in the interrupting chamber as the actuating gas of the control means, such control means do not make it possible to guarantee a fast opening/closing/opening cycle, because of the time required to remove the pressurized gas to the atmosphere and to bring the portions that have been connected to the atmosphere back under pressure after opening.